Various proposals over the years have been suggested for the purposes of creating an apparatus for the mechanical separation of cat solid waste randomly buried in cat litter. The cat litter is generally entrained not only with the solid waste but is saturated with cat urine waste that coalesces the cat litter into clumps. Separating the urine clumps of waste and solid waste is not an enjoyable task.
Various proposals have been proposed. For instance, PIERSON in U.S. Pat. No. 4,846,104 issued 17 Oct., 1978 discloses an AUTOMATED CAT TOILET featuring a rotary drum with an internal sieve member that is a fixed member within the cylinder and on rotation of the cylinder, passes through the cat litter to collect the solid waste and the clumps of saturated urine litter and upon further spinning, discharges them out of the cylinder into a collection region or tray beneath the same.
CARTER in U.S. Pat. No. 1,128,264 issued on 17 Oct., 1978 discloses a SANITARY FACILITY FOR PETS, being a rotatable drum chamber that accomplishes the same.
These inventions are cumbersome, have moving parts, and are expensive.